A hole near the master bedroom window of a Dublin, Calif. home marks the exit point of an errant cannonball fired during a filming of an episode of the Discovery Channel's "Mythbusters." Sheriff's deputies are still measuring how, exactly, the cannonball flew from a bomb range in the rolling hills flanking a suburban San Francisco Bay area neighborhood and rocketed into the front door of a home and through its master bedroom before landing in a neighbor's parked minivan. (AP Photo/Ben Margot)

The cast iron cannon ball, which was described as being between the size of a softball and the size of a cantaloupe, crashed into – and out of – one home, struck a roof across the street and then crashed through the window of a minivan.

View full size"Mythbusters" stars Adam Savage, right, and Jamie Hyneman speak to the media outside the home damaged by an errant cannonball fired during a filming of an episode of their show in Dublin, Calif. (AP Photo/Ben Margot)

The projectile was traveling at a reported 1,000 feet per second.

In an interview with KTVU TV, Sgt. J.D. Nelson of the Alameda County Sheriff's Department, who frequently appears on the show as a technical expert, said "This cannonball was supposed to pass through several barrels of water and a cinder block wall to slow its inertia. When the shot was fired, it misfired. The cannon lifted."

The cannonball apparently hit something that caused it to shoot over the hillside that protects the neighborhood below, he said.

Dublin Police Services is investigating the December 6, 2011 incident involving an errant cannonball that struck at two homes and damaged a vehicle in the City of Dublin. The television show “Mythbusters” was filming an episode at the Alameda County Sheriff’s Office Regional Training Center at the time.
Representatives of the “Mythbusters” program and the Alameda County Sheriff’s Office are cooperating with the investigation.
The City does not have jurisdictional oversight of activities that occur at the County’s Training Center, but City Manager Joni Pattillo has been in contact with the Sheriff’s Office to discuss the incident.
Sheriff Greg Ahern has advised the City that he has suspended all non-emergency activities at the Sheriff’s Bomb Disposal Range until the completion of a full investigation into this incident.

Meanwhile the show's hosts, Adam Savage and Jamie Hynemen, went to Dublin to meet with family whose house they punctured.

Savage told the Los Angeles Times
"We feel really lucky and fortunate that, after a nearly perfect safety record over eight years, that this mishap didn't lead to anybody being injured."

Shootiing of the segment was immediately halted and the Mythbusters team is reviewing what happened.

"We're gathering all the information we can ... Our main concern is making sure this never happens again," he said.

He added that he and Hyneman were not present at the time. The experiment was being conducted by co-hosts Tory Belleci, Kari Byron and Grant Imahara.